Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Consolidated Statements of Comprehensive Income (Unaudited) [Abstract]
Net income	$ 13,313	$ 14,558
Net unrealized holding gain on securities available for sale	10,732	4,588
Reclassification adjustments for net gain recognized in income	(1,155)	0
Tax effect	(2,487)	(1,192)
Net unrealized gain on securities available for sale, net of tax	7,090	3,396
Amortization of net actuarial gain	(166)	(48)
Amortization of prior service credit	(49)	(85)
Tax effect	56	35
Amortization of net actuarial gain and prior service credit on pension and postretirement plans, net of tax	(159)	(98)
Other comprehensive income (loss), net of tax	6,931	3,298
Comprehensive income	$ 20,244	$ 17,856